The invention relates to a drive mechanism for a sheet feeder device and its arrangement on a rotary printing machine.
A pneumatic sheet feeder device transfers the paper sheet from a pile and transports the sheet to the transport device which brings the sheets in superimposed arrangement to the printing cylinders.
The scope of the present invention is to provide a drive mechanism for a sheet feeder device consisting of a box, in which the mechanisms of the sheet feeder are arranged which are driven by a common drive shaft which enables the adjustment of the feeder device according to the size of the paper sheet to be printed and also enables the vertical setting of the feeder device.
Sheet feeder devices are known which are driven by means of a push crankshaft which allows for changing the position of the feeder device. The drive shaft of this device is arranged in such a way that the longitudinal axis of the shaft is located vertically to the direction of the movement of the fed sheets to be printed.
A disadvantage of the named device resides in the fact that the rotation of the drive shaft and that of the whole feeder device are not equal due to the influence of the push crankshaft. Also the production of the push crankshaft is complicated and expensive.
A further disadvantage of the device is that there arises during the adjustment of the feeder device a shifting (displacement) of the whole working cycle of the feeder device relative to the working cycle of the printing cylinders.
Another known sheet feeder device comprises a drive shaft which is arranged in such a way, that the longitudinal axis is parallely arranged with the horizontal plane of the sheet pile in the direction of the feeding of the paper sheets. The drive of the shaft is carried out by means of gears and by a rigid connecting shaft. The rotary movement and with this also the operation of the whole sheet feeder device is uniform.
A disadvantage of this feeder device is that the drive shaft, when the device is set for sheets of smaller size (form), is shifted out over the transport device, so that access to the device by the operator is impossible. Another disadvantage is that the rigid connecting shaft makes an adjustment of the feeder device according to the height impossible.
A further known feeder device is arranged on a carrier bracket which is fixed in the side wall of the printing machine. In a special box which also is attached to the side wall of the machine, there is arranged the drive for all mechanisms of the sheet feeder device which are arranged and controlled by means of pull rods.
A disadvantage of the device is in that it cannot be adjusted for height for the reason that while adjustment of the mechanisms should be shifted in their working position, this cannot be done due to the rigid connection of the pull rods.